1. Field of the Invention
The present invention relates to a traffic lane guidance system for a vehicle and a traffic lane guidance method for a vehicle for guiding a vehicle to a traffic lane so as to suppress the occurrence of sudden lane change of a vehicle.
2. Description of Related Art
In a navigation system mounted on a vehicle, guidance of a route from a current point as a first point and a destination point as a second point is carried out using voice, images, or the like. A navigation system for guiding an optical traffic lane for a running vehicle has been developed.
For example, in a driving support system described in Japanese Patent Application Publication No. 2012-221353 (JP 2012-221353 A), the occurrence probability of sudden lane change when a vehicle enters a point of intersection from traffic lanes is calculated as statistical information of right turns and left turns. By guiding a vehicle to a traffic lane in which the vehicle has to run in the vicinity of the intersection on the basis of the calculated statistical information, the occurrence of sudden lane change when the vehicle enters the point of intersection is suppressed.
However, in the driving support system described in JP 2012-221353 A, the lane change frequency occurring while a vehicle runs from a point of intersection to a subsequent point of intersection is not considered at all. Accordingly, when the lane change frequency of a vehicle increases in a route portion other than the points of intersection in the entire route from a current point to a destination point by guiding the vehicle to a traffic lane in which the vehicle has to run in the vicinity of the points of intersection, the occurrence of sudden lane change of the vehicle in the route portion may be rather promoted. That is, in the driving support system, an optical traffic lane in the vicinity of a point of intersection is guided on the basis of local information for each point of intersection so as to suppress the occurrence of sudden lane change when the vehicle enters the point of intersection. Accordingly, when the entire route from the current point to the destination point is considered, it cannot be said that the guided traffic lane is necessarily an optimal traffic lane for suppressing the occurrence of sudden lane change of a vehicle.